Vizio VX32L turns on with backlight, no video or sound

[vipertech]

Re: Vizio VX32L turns on with backlight, no video or sound

I saw the post about U15.....does anyone know where to purchase it? I seem to be having problems doing a search by the numbers and markings on the component. Thanks again for all the help all you have given.

[sportsman99]

Re: Vizio VX32L turns on with backlight, no video or sound

PLain Bill, YOUR the MAN!!,, i replaced U15 and the TV is working fine. odd to me tho when i replaced U15 i couldn't read voltages on U15 like VI VO but yet TV turned on and worked fine. O well,,, all good that ends good, thanks so much,,

[PlainBill]

Re: Vizio VX32L turns on with backlight, no video or sound

Plain Bill could i get you to respond to this update, PLEASE,,, thanks,

There may be something wrong with U15. I can't be sure because you only give 2 significant figures, I would expect the voltage on pin 2 to be 1.25 volts greater than the voltage on pin 1. It is only .9 volts higher, but I'm not sure if that is due to your using too high a range.

PlainBill

[sportsman99]

Re: Vizio VX32L turns on with backlight, no video or sound

Plain Bill could i get you to respond to this update, PLEASE,,, thanks,

[sportsman99]

Re: Vizio VX32L turns on with backlight, no video or sound

Okay, so i took some pic's and i labeled one called 4533M (to help see location)- here are the voltages i read with tv plugged in to AC and nothing else.

u15 Gnd Vo Vi
1.4 2.3 5.13

u19 1.2 2.4 5.13


u21 0.1 1.2 2.4


u44 0.01 1.2 2.4


u22 2.02 3.3 5.15



u17 2.0 3.3 5.15


thanks,, maybe i just need to purchase a handful amc1117 and go to soldering. BTW these are all amc1117


thanks,

[PlainBill]

Re: Vizio VX32L turns on with backlight, no video or sound

Sorry,, i will have to try a different camera to take pics with, from this one they will not upload, thanks,

Perhaps the pictures are too large? I recommend VuePrint Pro for resizing. Cropping, resizing, and saving is a simple 3 step process. It's free, note the serial number on the download page.

PlainBill

[sportsman99]

Re: Vizio VX32L turns on with backlight, no video or sound

Sorry,, i will have to try a different camera to take pics with, from this one they will not upload, thanks,

[PlainBill]

Re: Vizio VX32L turns on with backlight, no video or sound

I have a VW32l-HDTV20 with similar issue. after reading the forums i need help also. the unit had a pop sound then quit, when powered the vizio stays amber one the front. it will show no other signs of life, the power supply has 5v but i can not get 12v or 24v at the power supply. i checked the main board as follows.
f1 is good and has 5v on either side, f2 is good and no voltage on either side. u17 on center leg has 3.5v, u15 low V 2.5, U21 low of 1.5v possibly lack of voltage from u19?? u19 has 2.8v. i dont have a u33 at all. im guessing a bad power supply, i cant see any voltage past the transformers. but yet i do have 5 v on the edge connector. so does anyone know for sure my problem or do i have multiple problems?, i would like to trouble shoot the PS, any suggestions. does the unit need to be on to see 12v.24v? i dont see any signs of popped components or burnt anything. thanks,

1. The power supply is a dual unit, standby and main. The standby section (typically 5 volts) is on whenever the TV is plugged in. The main board switches on the main section of the power supply.

Obviously you have a different version of the main board. I suggest posting a picture of your main board and another of your power supply. Sharp, well lit pictures at a resolution of close to (but not over) 2000 x 2000 pixels are best. Attach them using 'manage Attachments" below the text entry area. If you also list the part numbers of the ICs you listed above, it will be easier to identify the problem.

PlainBill

[sportsman99]

Re: Vizio VX32L turns on with backlight, no video or sound

I have a VW32l-HDTV20 with similar issue. after reading the forums i need help also. the unit had a pop sound then quit, when powered the vizio stays amber one the front. it will show no other signs of life, the power supply has 5v but i can not get 12v or 24v at the power supply. i checked the main board as follows.
f1 is good and has 5v on either side, f2 is good and no voltage on either side. u17 on center leg has 3.5v, u15 low V 2.5, U21 low of 1.5v possibly lack of voltage from u19?? u19 has 2.8v. i dont have a u33 at all. im guessing a bad power supply, i cant see any voltage past the transformers. but yet i do have 5 v on the edge connector. so does anyone know for sure my problem or do i have multiple problems?, i would like to trouble shoot the PS, any suggestions. does the unit need to be on to see 12v.24v? i dont see any signs of popped components or burnt anything. thanks,

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

Glad you got yours working. I am leaving tomorrow to go back to school, break's over . I'll have to wait until the school year's over before I can work any more on this. I'll bump the thread then and see if I have any new ideas.
Thanks

[1simtime]

Re: Vizio VX32L turns on with backlight, no video or sound

I got a picture!
I replaced U33,U7,U9 voltages were low for all three on the board -off the board only U33 appears bad. I had to remove some caps to get to U33,U7,U9. They did not unsolder very well! Must be GND planes. I removed 5 100uF 16V( measured 71uF-79uF) and 3 220uF 25V (Measured 191uF -199Uf).I wonder how many other caps are out of tolerance or bad ESR ( I still don't have ESR meter).I replaced the 8 caps.
Have not fully tested all functions yet but I have to turn the volume up to 50 + to hear it , even maxed at 100 it is not super loud.
Anything else to check before I put it together?
Thanks for all the help and I hope we can still help Ayelix !!!!!

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

Yep, no change on mine. It looks like all the voltages are correct, is there another part of the board I should look at?

[1simtime]

Re: Vizio VX32L turns on with backlight, no video or sound

I plan to order from Digi- Key # 497-1229-1-nd for the amc1117 F0646J
I will post back when I get it replaced Thanks

I think Ayelix is still working on fixing a VX32L so I hope we can help !

[cadiman]

Re: Vizio VX32L turns on with backlight, no video or sound

I would go after u33 1simtime. my readings are from A GOOD WORKING BOARD ON A WORKING TV THAT I AM WATCHING A MOVIE ON.

1)As long as you get the same readings I have or not it will get you headed in the right direction, if we are lucky.

2)When an amc1117 fails I am pretty sure they go low.

3)Check with Plainbill

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

Here are my readings using the board ground instead of pin 1 of the regulators. Nothing looks wrong here . Also, it all matches the correct values in the DC-DC troubleshooting section of the VW32L service manual.

Component	SB out	SB in	ON out	ON in	
U10		0	0	2.62	4.99	
U7		0	0	1.24	3.29	
U9		0	0	1.49	3.29	
U33		0	0	3.3	5	
U8		3.3	5	3.3	5.04	
U2		0.12	0	3.33	5	
U4		0	0	3.28	5	
U3 		0		11.93		Pin 1
U3 		0		5.02		Pin 3
U1 		0	?	5	?	Pins 1,3,5,6,7,8
U6 		0	?	1.6	?	Pins 5,6

J1:
   Pin 1      PWR ON (about 3.3V? Mine's 1.7V)
   Pins 2,3,4,5   12V ON
   Pins 6,7,8    GND
   Pins 9,10,11   5V SB

F1: 12V ON
F2: 5V SB

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

Should I be using the board ground with the adjustable regulators and pin 1 for the fixed regulators? If that is the case then all readings should just be taken using board ground right?
Thanks for the help.

[PlainBill]

Re: Vizio VX32L turns on with backlight, no video or sound

I took all my readings today. It seems that the inputs for almost all the 1117 converters are low, ~3V instead of 5V. I recorded the standby (SB) in and out voltages and the power on (ON) in and out voltages. Pin 1 was used as ground, the larger tab (connected to pin 2) was used for out readings, and pin 3 was used for in readings.

Component  SB out  SB in  ON out	ON in
U10     0    0    1.25   3.62
U7      0    0    1.24   3.29
U9      0    0    1.24   3.04
U33     0    0    1.24   1.94
U8      1.24   3.04   1.24	2.98
U2      0.04   0.19   1.25	2.93  *See below
U4      0    0    1.24   2.97
U3      0         11.93      Using P2 GND, P1 V+
U3      0         5.02       Using P2 GND, P3 V+

I think these readings are different than what I saw a couple days ago. I think it may be because I was using the board ground (a mounting screw) during my readings instead of pin 1 of each converter.
U2 is interesting. It reads very low on standby, but as long as the reset button is held down it goes to ~3V in and ~1.24V out. Once the reset button is released it goes back to the very low input and output. I don't really know what to make of all this!
I'm going to go check all of the power connections again and I will edit this post to add those readings.

One point to consider, the AMC, AS, LM, etc 1117 regulators come in variable (AS1117) and fixed (AS1117-33; AS1117-25; etc) versions. On a fixed output version, pin 1 is at Gnd. On a variable output version pin 1 is the Adj input, and will be at some voltage above gnd. As you noticed, it is important to choose the Ground point for your measurements carefully.

PlainBill

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

I took all my readings today. It seems that the inputs for almost all the 1117 converters are low, ~3V instead of 5V. I recorded the standby (SB) in and out voltages and the power on (ON) in and out voltages. Pin 1 was used as ground, the larger tab (connected to pin 2) was used for out readings, and pin 3 was used for in readings.

Component  SB out  SB in  ON out	ON in
U10     0    0    1.25   3.62
U7      0    0    1.24   3.29
U9      0    0    1.24   3.04
U33     0    0    1.24   1.94
U8      1.24   3.04   1.24	2.98
U2      0.04   0.19   1.25	2.93  *See below
U4      0    0    1.24   2.97
U3      0         11.93      Using P2 GND, P1 V+
U3      0         5.02       Using P2 GND, P3 V+

I think these readings are different than what I saw a couple days ago. I think it may be because I was using the board ground (a mounting screw) during my readings instead of pin 1 of each converter.
U2 is interesting. It reads very low on standby, but as long as the reset button is held down it goes to ~3V in and ~1.24V out. Once the reset button is released it goes back to the very low input and output. I don't really know what to make of all this!
I'm going to go check all of the power connections again and I will edit this post to add those readings.

[Ayelix]

Re: Vizio VX32L turns on with backlight, no video or sound

I have not touched it since I made the post. Tomorrow I will take readings of all the DC-DC converters on the board and record my results.

[1simtime]

Re: Vizio VX32L turns on with backlight, no video or sound

Ayelix, are you getting anywhere with your VX32?